In the wire and cable industry, it is conventional practice to ship wire or cable wound on reels to a user. After unwinding the wire or cable from the reel, the user either disposes of the reel, or returns the reel for re-use.
A reel is composed of a cylindrical drum or core having flanges at its opposite ends for retaining cable, wire, or the like wound around the drum. To facilitate shipment of exhausted reels, various knockdown or collapsible reels have been designed. In a typical knockdown reel, the core is composed of two complementary, interlocking, semi-cylindrical parts which, when together, provide a circular, cylindrical outer surface. The two semi-cylindrical parts interlock with a pair of flanges to form a complete reel.
One such knockdown reel is described in U.S. Pat. No. 3,940,085, granted Feb. 24, 1976 to Kenneth E. Campbell. In the reel described in the Campbell patent, each of two semi-cylindrical core halves is formed with an arcuate ridge at both of its ends. The ridges are received in annular grooves formed in bosses on a pair of flanges. The core halves are secured to each other by bolts, and when they are secured together, the arcuate ridges are locked in the annular grooves, and the core and flanges are rigidly held together.
Another knockdown reel is described in U.S. Pat. No. 5,575,437, granted Nov. 19, 1997 to Kenneth E. Campbell. In this reel, semi-cylindrical core halves are connected to circular recesses in specially formed flanges by means of resilient, axially extending, latching fingers.
In still another knockdown reel, described in U.S. Pat. No. 5,806,788, granted on Sep. 15, 1998 to Richard P. Witwer and Kenneth E. Campbell, core halves are formed with locking fingers that engage notches formed on the peripheries of core-supporting hubs fastened to flanges.
Although the knock-down reels described in these patents have served reliably in the cable industry for many years, there remains a need for a more robust reel that can withstand impact, temperature variations and other forms of stress more reliably. For example, it is important for a reel to be able to withstand the impact that results when it is dropped from a fork lift or from the bed of a flat bed trailer.